Wanting to use CFW (coming from 3.41) but have a few questions

So I have been using 3.41 with the TI-84 JB on a 250GB slim, but I would like to be able to play newer games. I know that there are ways to get some of them to play, but I seem to fail at correctly editing the files. Also I want to be able to play Marvel vs Capcom 3 when it comes out (assuming it will run on 3.55 of course). Not having to use the calculator all the time would be great too. With there being a few options when it comes to CFWs, I am wanting to make sure I don't mess-up. So my questions are as follows.

1. What files do I need to make sure are saved before updating? I don't want to loose blu-ray support in the event of needing to downgrade, or whatever other reasons it might be lost. And I of course don't want to loose anything else that could be lost.

2. If I need to use the backups of the files from question 1, how do I go about restoring them to working order?

3. Which CFW(s) allow creating and playing backups of games? I try to stay current, but I know some of them did/do not support running backed up games.

4. Are there current backup managers that seem to work better than others on CFWs (or at least specific CFWs)?

5. Of the CFWs that can load backups. Which ones are fairly easy to install? I can follow instructions pretty well in most cases, but I really want to avoid a brick (as I imagine everyone does).

Any input is helpful. I am sure that some (or all) of this may be in other threads, but I want to make sure I have the latest info. I just want to make this happen as smoothly as possible. And it may be helpful to more than just myself.

I like kmeaw as well. I came from 3.41 and updated to the official 3.55 then used the recovery menu (hold power) to flash to kmeaw. To try and answer your questions..

#1 you won't lose bluray playback unless you have a fat (256 nand)
your slim will be fine, but still backup EVERYTHING just in case and while you have access to it.

#2 if you FTP'd everything to your PC as a backup, if you needed it you'd just FTP it back

#3. Which CFW(s) allow creating and playing backups of games? Hermes 3.41CFW is a great choice if you're coming from a dongle... because all of your PSN game and hacked eboots you've already got set up just work. Otherwise kmeaw I know also allows ripping + playing.

4. Back up managers - I used to use gaia and recently got hooked into the multiman train of constant updates. Both are solid, multiman is turning into the XBMC jacknife app.

5. Of the CFWs that can load backups. Which ones are fairly easy to install? I can follow instructions pretty well in most cases, but I really want to avoid a brick (as I imagine everyone does).

Hermes was easier than kmeaw because it just installed via the normal menu instead of having to go into recovery mode. mPros and cons to all CFWs. You may want to wait for a 3.56 or 3.6 CFW for access to PSN again, you might want to try Hermes and ditch the calculator/dongle.. or just go for 3.55 kmeaw and enjoy running all the new games with the newest updates etc.

#1 you won't lose bluray playback unless you have a fat (256 nand)
your slim will be fine, but still backup EVERYTHING just in case and while you have access to it.

#2 if you FTP'd everything to your PC as a backup, if you needed it you'd just FTP it back

I want to backup everything, but I have never been able to get FTP to work correctly. I have been able to "see" the PS3 on my computer with FileZilla and BlackBox. But I could not ever get it to allow moving files to the PS3. And as such I am a bit worried that anything I can get off the PS3 might not actually be complete.

Can it be done by copying the files to a USB drive/external HDD? What files do I copy? Using multiman's file manager I can see app_home, dev_flash, dev_flash2, dev_flash3, dev_hdd0, dev_hdd1, and ps3_home. But it only will let me create folders, not copy them (or at the very least, none of the buttons in the version I have seem to be mapped for copy in the file manager). If FTP is the only way. How does it need to be setup (a link to an up-to-date howto is okay)? Also, thanks for the provided answers.

Aside from the stuff above, I believe I will try the kmeaw 3.55 CFW. The instructions I have read seem to be very easy.

1.To save your blueray in the event you downgrade backup your flash 2 and flash 3 as said above if you have a slim your fine just the fat PS3s lose blueray when downgrading

2. You use the FTP server or file manager
and to be honest i use windows explorer as my ftp client (open my computer and in the address bar type ftp://192.168.x.xxx) i find this to work better than filezilla or other ftp clients

3. as said above Hermes CFW of Kwmens 3.55 also works

4. multiman seems to work the best for me becuase the payload is built in i dont know about any others i havent tried.

5. Kwmens is pretty easy just install 3.55 offical then you should be able to put kwmens on a flash drive on update via sysem update on the xmb